1. Field of the Invention
The present invention relates to an endoscope device which is inserted into the body cavity and is used together with a device such as a flexible endoscope.
2. Description of Related Art
Conventionally, endoscope devices are used for observing and treating an affected area or the like within the body cavity of the subject. Endoscope devices are known in which an elongated and flexible insertion part which is inserted into the body cavity from the distal side, and an operating part for operating the insertion part are provided so as to connect to each other.
The distal portion of the insertion part is provided with an observation main body for observing the periphery, and a distal end construction part on the distal end surface of which two arm members into which treatment tools for performing treatment are inserted are provided. A bendable tuber bending part is connected to the proximal side of the distal end construction part, and a flexible tuber part which is connected with an operating part is connected to the proximal side of the bending part. A distal portion of an operating wire inserted into the bending part and the flexible tuber part is fixed to the proximal side of the distal end construction part, and the proximal portion of the operating wire is attached to an angle knob which is provided in the operating part and pulls the operating wire.
Instrument channels are formed so as to extend from the distal portions of the two arm members to a forceps plug provided in the operating part via the insertion part. By inserting the treatment tools into the instrument channels, treatment can be performed with the distal portions of the treatment tools protruded from the distal ends of the arm members.
In the endoscope device constituted as above, the insertion part is inserted into the body cavity of the subject while observing the periphery by using the observation main body and bending the bending part by using the angle knob so that the distal portions of the treatment tools do not protrude from the distal ends of the two arm members. Then, the insertion part is fixed so that the two arm members are opposed to the affected area and the distal end portions of the treatment tools are protruded from the distal ends of the arm members to perform treatment.
However, with the above-described conventionally endoscope devices, since the distance between the observation main body and the proximal ends of the two arm members is short, the proximal portions of the two arm members extensively appear on the field of view via the observation main body. As a result, it is difficult to observe the state of treatment performed by the treatment tools by using the observation main body. When making the distance between the observation main body and the proximal ends of the two arm members large, since the diameter of the insertion part also becomes large, the insertion ability reduces.